Hello!
I have need for tagging that a restriction on a road is only valid in
case a vehicle is driving uphill.
The traffic sign states "Snow chains required when ice or snow on road,
except for AWD cars driving uphill"[1]. This is indicated on both sides
of the road section, both driving uphill and downhill.
That would call for a conditional [2] specification of a direction or
condition with the aspect of direction in relation to elevation.
The first idea was to use 'incline=up' like in
snow_chains=required @ (ice; snow)
snow_chains:motorcar:conditional=default @ (awd AND incline=up)
It was pointed out[3] that 'incline' is a tag and intended to indicate a
*direction* and amount of inclination of *the road in relation to the
mapping direction*, not the direction of the *vehicle driving* on the road.
**'uphill'** was proposed.
There is however a accepted specification for relative direction
longitudial-wise in relation to the way: Forward, backward, left, right
[4][5][note 1].
These are defined to be used as key suffix or value.
The improvement seems to be to instead use 'uphill' either
as direction as key suffix
snow_chains=required @ (ice; snow)
snow_chains:motorcar:uphill:conditional=default @ awd
or as condition
snow_chains=required @ (ice; snow)
snow_chains:motorcar:conditional=default @ (awd AND uphill)
The direction key suffix approach seems to integrate better, but mappers
could mistake it and use it instead of :forward and :backward, making it
impossible to interpret without inlination information. Using it in the
condition seems to split direction information from other direction
information.
What do you think?
Best Regards
Patrick/trapicki
[1]
https://wiki.openstreetmap.org/w/index.php?title=Proposed_features/Snow_chains&oldid=2451441#Examples
[2] https://wiki.openstreetmap.org/wiki/Conditional_restrictions
[3]
https://wiki.openstreetmap.org/wiki/Talk:Proposed_features/Snow_chains#uphill_vs._incline
[4] https://wiki.openstreetmap.org/wiki/Forward_%26_backward,_left_%26_right
[5] https://wiki.openstreetmap.org/wiki/Proposed_features/right_left
[note 1] I could not find an accepted proposal for that, bit was
implicated in the the proposal for conditional restrictions that it was
accepted at that time of the :left and :right proposal in 2009
https://wiki.openstreetmap.org/w/index.php?oldid=813491#What_about_:forward_and_:backward?
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Increase the Awesome, reduce the WTF!
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